1. Field of the Invention
The present invention relates to lane boundary line recognition devices and computer-readable storage mediums for storing programs capable of recognizing lane boundary lines on a roadway on which an own vehicle drives on the basis of images captured by an in-vehicle camera, and assisting a driver of the own vehicle in order to perform driving safely.
2. Description of the Related Art
There are various techniques of recognizing lane boundary lines on a roadway, on which an own vehicle drives, on the basis of images of the roadway captured by an in-vehicle camera, etc., and performing a driver assist of the own vehicle on the basis of the recognized lane boundary lines. There has been proposed a driver assist technology capable of suppressing recognition of lane boundary lines on a roadway, on which an own vehicle drives, when the vehicle drives on a roadway which is not suitable for correct recognition of the lane boundary lines on the roadway.
For example, a patent document 1, Japanese patent laid open publication No. 2001-88636, discloses an external observation device mounted on a vehicle. This external observation device performs a fail safe operation which temporarily interrupts a usual observation control when the vehicle is running on a snowy road, i.e. a snow-covered road and snow lies on shoulders of the snowy road because it is difficult for the external observation device to obtain adequate information for correctly detecting lane boundary lines such as white lines on the snowy road.
The external observation device according to the patent document 1 judges the condition of the roadway on the basis of instantaneous images captured by the in-vehicle camera of the vehicle. This introduces a possible problem of it being difficult to suppress the recognition of the lane boundary lines stably. On the other hand, when using a filter to perform the stable recognition operation, the external observation device provides a possible problem of it being difficult to quickly restart the recognition of lane boundary lines immediately after the road condition has changed to be suitable for performing a correct recognition of the lane boundary lines on the roadway.